That's what I thought you'd say.

4 seconds sound clip from the Miracle on 34th Street (1947) movie soundboard.

You can hear this line at 00:43:54 in the Blu-ray version of the movie.

Quote context

[...]

- Yes, I understand that, but there must be something you want for Christmas, something you haven't even told your mother about, eh?

- Ah, come on now. Why don't you give me a chance?

- Well...

- That's what I want for Christmas.

- You mean a doll's house like this?

- No, a real house. If you're really Santa Claus, you can get it for me. And if you can't, you're only a nice man with a white beard, like Mother said.

- Now, wait a minute, Susie. Just because every child can't get his wish, that doesn't mean there isn't a Santa Claus.

- That's what I thought you'd say.

- No, but don't you see, dear? Some children wish for things they couldn't possibly use - like real locomotives or B-29s.

- But this isn't like a locomotive or a B-29.

- It's awful big for a little girl like you. What could you possibly do with a house like this?

- Live in it with my mother.

- But you've got this lovely apartment.

- I don't think it's lovely. I want a backyard with a great big tree to put a swing on and...

[...]